Apparatus for advancing material



12, 1954 H. R. LEYPOLDT ETAL 2,665,797

APPARATUS FOR ADVANCING MATERIAL Filed April 25, 1949 2 Shets-$heet 1 INVENTORS HR. LE YPOLDT A TSTODDART A T TORNEV Jan. 12, 1954 H. R. LEYPOLDT HAL 2,665,797

APPARATUS FOR ADVANCING MATERIAL Filed April 23, 1949 2 Sheets-Sheet 2 INVENTORS H. R. LEYPOLDT A. 7.'STO DART ATTORNEY Patented Jan. 12, 1954 APPARATUS FOR ADVANCING MATERIAL Harry R. Leypoldt and Adam 1:. Stoddart, Baltimore, Md., assignors to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York Application April 23, 1949, Serial N0. 89,338

Claims. 1

This invention relates to apparatus for advancing material, and more particularly to apparatus for advancing weighed material to conveying apparatus.

In some manufacturing processes, such as, for example, in compounding plastic compounds, the ingredients frequently are weighed in batches by weighing devices, and must be advanced from weigh-pans of the weighing devices to points of use thereof. Vibratory devices have been proposed in the past for vibrating weigh-pans to advance weighed material therefrom, but these vibratory devices have been deliberately weighted on the theory that excess weight was necessary to operativeness. As a result, the vibratory devices have been so heavy in proportion to the weight of the material weighed that accuracy .of the weighing operation has not been so high as it might have been if the advancing devices-were lighter. No advancing devices of unweighted, light weight construction for accurate weighing have been known in the past.

An object of the invention is to provide new and improved apparatus for advancing material.

A further object of the invention is to provide new and improved apparatus for weighing and advancing material. Another object of the invention is to provide a pan type weighing and transferring device n of such light construction that the weight of the weighing and transferring device is low in proportion to the material being weighed in each batch. .l. An apparatus illustrating certain features of the invention may include a pan, a flexible arm connected rigidly to the pan, an armature connected rigidly to the pan, electromagnetic-fieldcreating means connected rigidly to the arm, and means for energizing and deenergizing the field-creating means.

A complete understanding of the invention may be obtained from the following detailed description of an apparatus forming a specific embodiment, thereof, when read in conjunction with the appended drawings, in which:

- Fig. 1 is a front elevation of an apparatus forming one embodiment of the invention, and Fig.2 is an enlarged, fragmentary, front elevationpf a portion of an apparatusshown in Fig. 1. p

, Referring now in detail to the drawings, weighing devices [0, I2 and I4 periodically supply powdered. ingredients of a thermoplasticcompound t am r l6. wh ch m bee the o 0 m:

2 prising the subject matter of copending application, Serial No. 89,358, filed April 23, 1949, by 0. B Clotworthy, for Methods of an Apparatus for Mixing Materials, now Patent No. 2,592,245, issued April 8, 1952. A metering device I8 also supplies liquid periodically to the mixer I8. Each of the devices I 0, l2 and I4 is similar in construction and operation, and for simplicity of description only the weighing device 10 will be described in detail.

The weighing device It! includes a hopper 20, which has a valve-controlled discharge spout 22. Powdered material is dropped from the spout 22 into fall-breaking pan 23 directed perpendicularly with respect to a receiving weigh-pan 24. The weigh-pan 24 is suspended by springs 26-26 from a channel 28 connected pivotally to a rod 30 supported by an arm 32 of ,a beam 33 forming part or a balance 34. A weight pan 36 is suspended from an arm 38 of the beam 33, and balancing weights 40-40 rest upon the pan 33. The beam 33 is mounted pivotally on an agate knifeedge 42 carried by an upright 43.

A rigid, generally U-shaped frame 44 (Fig. 2)

.- is connected rigidly to the heel end of the pan 24 by a reinforcing plate 46. Leaf springs 48 and 58 are connected to arms 52 and 54 of the i'rame 44 and to arms 56 and 58 of a second rigid, generally U-shaped frame 60. A light weight soft iron armature 62 is connected rigidly to the arm 52 of the [frame 44. A core 54 is connected to the arm 58 of the frame by a rigid arm 66 and an L-shaped bracket 68. A coil 10 is sup- Operation Powdered material is-dropped from the hopper 20 into the pan 23, and overflows from the discharge end of the pan 23 into the weigh-pan 24. When the weigh-pan has received sufilcient powdered material to equal a predetermined portion of the weights 40--40, the beam 33 moves to a level position, and actuates a suitable control system (not shown), such as the control system shown in Patent 2,100,874 to Ryan et al., to stop the flow of material from the hopper 20 and to energize the rectifier 14. When the rectifier 14 is energized, it supplies pulsating electrical current to the coil 10 varying from zero to a predetermined value and fromthis value back to zero at a frequency of 3600 times per minute. During each cycle of current flow through the coil 10, the armature 62 is drawn toward the core 64, and then the leaf springs 48 and 50 move these elements apart as the current dies in the coi1 10.

When the armature 62 is drawn toward the core 64, the core 64 and the frame'GO are pulled upward and to the left, as viewed in Fig. 2. This pulls the pan 24 downwardly and to the right sufficiently rapidly to pull the pan slightlyaway from the material in the pan and to the right relative to the material. The current to the coil '10 then is cut off, the field in the core 54' and the armature 62 dies, the material drops on the pan and the springs 48 and 50 swing the pan 24 slightly to the left, and move the frame an and the core 64 and the coil '10 to the right.

Thus, during each cycle of the current supplied to the coil 10, the pan 24 is moved downwardly to the right with respect to the material,- the material drops vertically on the pan at points on the panslightly to the left from those which they engaged previously, the material is moved slightly to the left, and the material is fed from the discharge end 8E3 thereof to the mixer until all the material in the pan 24 is emptied. As the material in the pan 24 is fed therefrom and thepan is emptied; the arms 32 and 38 of the beam 33 move in a clockwise direction, as viewed in Fig. 1, due'to the weights ill-40. After the pan 24 has been emptied, the current to the rectifier 7:4 is stopped, and the weigher it is ready for another weighing and delivery operation.

The assembly of elements including the weighpan '24 and the vibrating unit suspended therefrom has a natural frequency of vibration approaching the numerical value of, but slightly less than, the frequency at which the coil 79 is operated so hammering between the coil and armature is prevented and a high vibratory force is preserved. A natural frequency of this ass'em bly found to give excellent results in practice is 3510 cycles per minute when the frequency of the operation of the coil is about 3600 cycles per minute; The weight of the pan M is low, and the combined weight'of the vibraticn unit including the frames 54 and til, the" reinforcing plate 413, the leaf springs 38 and 55., the armature and the e'lectromagnet is even less than that of the pan. The elements of the vibrator unit are sumciently heavy in construction to provide only the mechanical strength and electrical characteristics necessary, and hence are unweighted. That no portion of any of these elements is mere ballast in contrast to the prior art vibratory devices in which theelectrOmtgnets are either deliberately weighted or arefixed to'a fixed object. However, even though the weight of the electromagnet is less than that of the weigh-pan, it,

has sufficient weight to vibrate the pan: to feed. material rapidly therefrom.

@In: one specific examplethe combined weight of the weigh-pan 24, the plate 46', the frame" 4'4, the armature 82, and half of both the springs 4 3' and 50' Was about 230. grams, and the combined weight of the elements iorming the other inertia body, namely: the electrcmagnet; the frame Ell, the bracket 5-8 and one-half. of both the springs 48: and 503 was about l'l lv grams. Excellent deliv-- ery results were obtained even. when the pan-Was heavily loaded although the weight of the elemerits causing vibration of the pan was only about. 43% of. the. total empty combined weight 4 while the weight of the vibrated elements was about 57% of this total.

The combined Weight of all the elements suspended by the arm 32 is so small that it balances only a small portion of the weights 4040 needed to balance these elements and weigh each batch of material. Hence, the balance 34 weighs each batch of material very accurately, it also delivers the material to the mixer rapidly after each weighing operation. The transfer unit is light and inexpensive in construction, is strong and durable, has a large capacity for each weighing 7 operation, and serves to discharge each batch of material weighed thereby in a very short period of time; The structure of the above-described weigh-pan and vibrating mechanism is such that they may even be suspended from and used continuously with a laboratory type agate-bearing beam balance without deleterious efiects on the fragile balance.

While the above-described transfer device is shown as a portion of a weighin device and very important in such a field of use, it obviously may be used wherever conveying of materials is needed.

What is claimed is:

1. A transfer device, which consists of a pair, a generally U-shaped frame secured rigidly to the base of the pan with the arms thereof projecting away from the pan, a pair of leaf springs secured to the arms of the frame, a second gen erally U-shaped frame connected to the leaf springs, an armature connected to one of the U-shaped frames, an electromagnet connected to the other U -shaped frame, and means for supply ing apulsating current to the electromagnet to vibrate the pan, the weight of the pan being greater than the combined weight of said other elements.

2. A transfer device, which'consists'of a can, a generally U-shaped frame secured rigidly to the base of the pan ina position thereof in which the arms project away from the pan, a pair 01 leaf springs secured to the arms of the U-shaped frame, a second generally U-shaped frame connee-ted to the leaf springs, an armature connected to oneof the U-shaped frames, an electromagnet connected to the other ill-shaped frame; and

means for supplying a pulsating current to" the electromagnet to vibrate the pan.

3. A transferdevice, which consists of a: pan, a generally U-shaped frame secured rigidly to the base of the pan with the arms thereof projecting away from the pan, a pair of leaf springs secured to the arms of the frame, a second U-shaped frame connected; to the leaf springs, an armature connected rig-idly to the first-mentioned" U-' shaped frame, an electromagnet connected rigid- 1y to the second-mentioned U-shaped frame, and means for supplying a pulsating cin'rent to the electromagnet to vibrate the pan, said second mentioned frame said spring elements and the electromagnet having a total weight that is lessmagnet to vibratethe pan, the natural frequency base of the pan with the arms thereof projecting 10 away from the pan, a pair of leaf springs secured to the arms of the frame, a second U-shaped frame connected to the leaf springs, an armature connected rigidly to the first mentioned U- shaped frame, an electromagnet connected rigidly to the second-mentioned U-shaped frame, and means for supplying a pulsating current of about 3600 cycles per minute to the electromagnet to vibrate the pan, the natural frequency of vibration of the springs being about 3450 cycles per minute said second-mentioned frame said spring elements and the electromagnet having a total Weight that is less than that of the pan.

HARRY R. LEYPOLDT. ADAM T. STODDART.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,617,301 Reddick Feb. 8, 1927 2,280,056 Broekhuysen Apr. 21, 1942 2,352,114 Musk-at June 20, 1944 2,407,357 Weyandt Sept. 10, 1946 2,444,134 Hittson June 29, 1948 2,462,286 Rhodes Feb. 22, 1949 2,467,748 Hittson Apr. 19, 1949 

